Upgrades for 4age 20v valves

[ATAl]

So this happened cranking the engine before it had ever been started





I think I screwed up badly and the valves may have hit the piston when I was turning the cam around and then broken when cranking, so I'm going to have to repair this now.

I see this as an opportunity to upgrade as this engine has higher lift cams and stiffer springs than factory so I might have problems with the factory valves in the future anyway.

So should I replace the valves with new factory ones or find some aftermarket stronger valves?

If aftermarket, who makes replacements for the 20valve?

Also, who, preferably in wellington, but if they are really good i'm willing to post the head, can install new valves and do some porting and a valve 3 angle job at the same time? Oh, and also repair the damage to the head.

Cheers.

[evil_si]

id be replacing that piston and rod at the same time

wierd that they broke like that, what was the cam timing like? looks like they have been held open for some reason and the piston has made full contact

[ATAl]

Once I cleaned it up the piston looks re-usable, there's a bit of gouging but nothing major that can't be cleaned off with a file, and as I think I did the damage while hand turning the cam I'm hoping the conrod is ok. Also, it's an aftermarket job and I really don't want to replace it as that won't be cheap

[evil_si]

at the least id be getting them checked out, ie crack tested and rod checked for straightness,

even if you were winding it over by hand you must have exerted some force to break 2 valves, what size bar were you using?

do you know why they made contact

[ATAl]

Was using a spanner on the camshaft, probably contacted because the piston was in TDC and I spun the cam around further than I ment to when turning it, causing the valves to lift a wee bit, and I guess hitting the piston.

But you're right, I should get it checked, and will. I'm just not looking forward to pulling the engine back out.

I don't think I broke that valves when turning it over by hand, my guess is that I bent them a bit, then when cranking over they tried to pull back into shape and snapped.

[sergei]

Is this the same engine that you had dizzy pointing at #2 on TDC?
Perhaps marks on the cam wheels are way off?

[Dell'Orto]

I think Ferrea do valves for 20v 4AGE's. As for headwork, send it to The Headshop in Palmy, they do very good work.

[ATAl]

Is this the same engine that you had dizzy pointing at #2 on TDC?
Perhaps marks on the cam wheels are way off?

Yip, is the same engine, when I fixed that problem, I caused this one, not my weekend really.

I think Ferrea do valves for 20v 4AGE's. As for headwork, send it to The Headshop in Palmy, they do very good work.

Had a look at their catalogue and they only seem to list 16v valves, cheers for the advice about The Headshop.

[matt dunn]

Yip, is the same engine, when I fixed that problem, I caused this one, not my weekend really.

Did you not have the cam wheel on the wrong dowell while cranking it over?
I'd say that bent and broke the valve, as that would have put the valves way out of sync,
and you would really struggle to bend a valve while turning the cam by hand with the engine at TDC.

[ATAl]

Did you not have the cam wheel on the wrong dowell while cranking it over?
I'd say that bent and broke the valve, as that would have put the valves way out of sync,
and you would really struggle to bend a valve while turning the cam by hand with the engine at TDC.

Yip, but the valve didn't break until after I had fixed the timing, cranked it over quite a few times then it went clunk and stopped moving.

[allencr]

What's been changed and/or replaced????????
Besides being non-interference, those valves should NEVER break, just bend, gotta be aftermarket crap.

Also, it should have happened to ALL 8 of them, or at least 4 if the engine was sitting still and the cam was rotated once. 2 pistons are always in the same position, so it can't happen on just a single cylinder.

[ATAl]

What's been changed and/or replaced????????
Besides being non-interference, those valves should NEVER break, just bend, gotta be aftermarket crap.

Also, it should have happened to ALL 8 of them, or at least 4 if the engine was sitting still and the cam was rotated once. 2 pistons are always in the same position, so it can't happen on just a single cylinder.

Cams are higher lift and pistons are 8.9:1 gze items, this probably makes this an interference engine as the cut outs are in place only for a 16v head.

As far as I know the valves are factory toyota.

The reason, as far as I can tell, that only 2 broke was that I only turned the cam far enough to push the valves on cylinder 4 into the piston, and that was accidental, I wasn't turning the cam around fully because I knew valves would hit the piston. So the valves on number 1 cylinder (also at tdc) are fine.

[ATAl]

I'm now sure that the valves broke because I stuffed up and turned the cam too far, so will replace them with factory items. So don't worry about my original question of what caused the damage or where to get upgraded valves.

But I'm still keen on hearing any more recommendations of places to go which will go a good job of porting the head and fixing the damage to the valve seat and face of the cylinder head.

[XSVWGN]

I had my blacktop head ported and polished with a grind as well as ned valve stem seals being put in for about $350.00 as a perky from darren at Kerry Lindseys

Matt

[CAMB01]

Kerry Lindsay Engine Reconditioners as i used to work there

[frost]

look at the steps on the valve stem,

would that indicate a few fracturing nudges rather then a one hit and break,
i remember seeing another valve just like that, and it broke from multiple hits.

was it very cold in your garage when you turned it over?

[ATAl]

was it very cold in your garage when you turned it over?

Not warm, but not completely freezing - normal wellington weather.

[AceSniper]

supertech do 1mm os valves best to import from US.
them seats are fukd.

[matt dunn]

Stupid question time,

Is it a silvertop head? and if it is not ported, why not bin it and get another. They are only worth about $50 s/h.

[AceSniper]

blacktop matt
super-tech valves are like 600 area imported and the work to fit them $$$$ there worth over 1k through the nz dealer